A press is a mechanical device that presses ink on a media side (such as paper and cloth). Its working principle is: first to print the text and images made of plate, mounted on the press, and then by the artificial or printing press the ink coated on the plate with text and images of the place, and then directly or indirectly Printed on paper or other substrates (such as textiles, metal plates, plastic, leather, wood, glass and ceramics), thus copying the same prints as the plates. The invention and development of the printing press play an important role in the spread of human civilization and culture.
1, screen printing machine working principle
To the usual hand-screen screen printing machine, for example, the screen printer can be described as follows: the transmission mechanism through the power, so that the squeegee in the ink squeeze ink and screen printing plate, the screen Printing plate and the substrate to form a stamping line, the screen has a tension N1 and N2, the production capacity of the fuser plate F2, the resilience of the screen printing plate in addition to embossing lines are not in contact with the substrate, the ink in the The squeeze force of the wiping plate F1 is applied to the substrate through the mesh, from the moving embossing line.
In the printing process, the screen printing plate and the wiping plate relative movement, squeeze force F1 and rebound force F2 also will be synchronized with the movement, the screen under the action of resilience, the timely return and the substrate from contact, so as not to Blotting dirty. That is, the screen in the printing process, constantly in the deformation and rebound.
Wipes in the completion of one-way printing and screen printing plate with the release from the substrate, while the return to Mexico, that is, to complete a printing cycle. After the ink on the back of the substrate and the screen printing plate on the back of the distance known as the same distance or net distance, the general should be 2 ~ 5mm. Manual printing, the operation of the workers and proficiency in the direct impact on the formation of embossing lines. In practice, silk screen workers accumulated a lot of valuable experience, the specific can be summarized as six points, that is to ensure that the drum plate movement in the linear, uniformity, isometric, uniform, neutral and vertical. In other words, the printing of the wiping plate should be straight forward, can not shaking left and right; can not be slow before the fast, fast after the slow or suddenly slow; to the ink plate tilt angle should remain unchanged, with particular attention to overcome the tilt angle Gradually increase the common disease; printing pressure to maintain uniformity; keep the doctorboard and the inside of the box on both sides of the same distance; to the ink board and the border to keep vertical.
2, flat screen surface printing machine works
Flat screen surface screen printing refers to the cylindrical or conical surface with a flat screen for screen printing. Under certain conditions can also be oval surface, drum surface, curved surface and other surface screen printing. Dry screen surface screen printing machine is the use of flat screen printing on the surface of the machine.
Flat surface with silk screen machine works: a-roller bearing b-axis bearing c-mosaic bearing. When printing, the flat screen printing plate and the substrate movement, while the scraping plate is still. The flat screen plate is held on the net frame by the flat screen surface screen printing machine with the action of constant speed translation, because the screen friction will be placed in the support device on the substrate with the rotation. The linear velocity of the substrate on the embossing line is consistent with that of the flat screen printing plate.
Theoretically, the embossing line should be printed on the surface of a bus at the highest, in order to facilitate the increase from the angle, to ensure the quality of printing. For the convenience of adjustment, the doctor blade generally use 60 ° ± 15 ° vertex, requiring vertical and up and down the size of the adjustment. Adjust the vertical is to ensure that the adjustment up and down when the edge of the cutting line does not produce a horizontal shift, always aligned with a maximum of a bus A; angle of 60 ° ± 15 ° of the wiper is to ensure that the vertical installation of the formation of the wiper angle α. In the actual adjustment, in order to ensure that the flat screen printing plate and the surface of the substrate in a timely manner from the embossing line can be appropriate before a little bit, especially when the substrate diameter is large, the imprint line must be partial, the surface printing support device is Various forms of special equipment, designed by the user according to product design and manufacturing.
Cylindrical containers or conical containers can be printed with two pairs of roller bearings, the length to diameter ratio of less than 1.5 cover and cup type sleeve support, flexible hollow containers can be inflated device support. The elliptical surface is approximately a part of the cylindrical surface and can be supported by a cylindrical mosaic approach.
The principle of printing on the surface of the cone is essentially the same as the principle of printing on the surface of the cylinder, except that the graphic shape of the screen plate and the form of the screen printing plate are different. In the production of the screen for the printing of the surface of the screen, we must first draw the surface of the cone, and according to the expansion of the center of the sector, and then select the appropriate screen production screen printing plate.
On the version of efgh, which can completely cover the fan-shaped abed, the plates are made in line with the fan. Fix the right angle bar on the version efgh and install it as a fan-shaped version with an o-axis. And then printed on the surface of the cylinder with the same, in the bottom of the plate with four rollers to support the substrate, the scraper was fixed, according to the fan-shaped mobile frame, scraper pressure can be tapered version of the surface printing. At the time of printing, the conical printing is in contact with the screen printing plate under certain pressure of the scraper plate. When the screen printing plate is moved horizontally in the fan-shaped expansion axis, the substrate is rotated synchronously on the supporting device Movement; ink squeeze in the squeegee, the printed matter to the surface of the substrate to complete the printing.
3, the printing process:
(1) flat screen flat screen printing machine working cycle program. To flat screen version of the flat-type semi-automatic hand-screen screen printing machine, for example, one of its working cycle is: to the material → positioning → down → down to the ink board, or back to the ink board → scraping → Board → drop back to the ink board → lift → back to the ink trip → release positioning → received.
In the continuous cycle of action, as long as the function can be achieved, each action takes as short as possible to shorten the working cycle of each period, improve work efficiency.
(2) Embossing lines. In the printing process, to the ink board squeeze the ink and screen printing plate, so that screen printing plate and the formation of a contact line, known as the imprint line. This line at the edge of the wiper blade, countless imprint lines constitute the printing surface. It is difficult to achieve the ideal embossing line because the printing stroke is a dynamic process.